A gene on the Y chromosome causes a rare disease. A woman married to a man with the disease has three children. The first two are daughters without the disease. The third is a son. What is the probability that the son will have the gene?
A) 0%
B) 25%
C) 50%
D) 75%
E) 100%
E
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Match the following items with the correct phrases.
_______1. _______2. _______3. _______4. _______5. a. Cryptosporidium parvum b. Ebola virus c. Escherichia coli O157:H7 d. Hantavirus e. Legionella pneumophila
You stumble upon an unidentified arthropod with no antennae and eight legs. This organism is likely closely related to
_____. a. grasshoppers b. ticks c. crayfish d. millipedes e. trilobites
Mycoplasma tuberculosis, the causative agent in tuberculosis, primarily infects the alveolar macrophages and is therefore very fortunate in its size. Why is this statement true?
A) It is just large enough to land in the mucociliary ladder, where type II macrophages phagocytize them. B) It is too small to be caught in the mucociliary ladder and too large to be immediately exhaled, thereby landing it in the alveoli. C) It is just small enough to land in the bronchi, where it is absorbed by alveolar macrophages. D) It is just large enough to land in the respiratory bronchiole, where it migrates to the alveoli. E) It is just small enough to land in the mucociliary ladder, where it is moved to the alveoli to infect macrophages.
Which one of the following nonhormonal chemical messengers is important in local control of blood flow and blood clotting?
A) prostaglandins B) nerve growth factor C) tumor angiogenesis growth factor D) histamine E) epidermal growth factor